摘要
本文拟用阴离子淀粉与壳聚糖作为双助剂共用,该双助剂能有技地提高纸张的物理强度和填料留着率。强度提高主要是由于双助剂增加了纤维间的结合面积及结合强度。壳聚糖的—NH_3^+基同纤维表面的COO基形成了牢固的离子键结合。壳聚糖、纤维、磷酸酯淀粉、填料之间的电荷中和所引起的絮聚及它们之间的架桥作用,提高了填料的留着率。
Effect of chitosan-starch phosphates on the paper strength and filler retention of the furnish of wood and reed fibers was investigated and the mechanism was discussed.The result showed that paper strength and filler retentiom increased significantly when 0. 2% chitosan and 3% starch phosphates were added at pH 5. 5.The Effect of the dual additive reduced with the molecular weight of chitosan decreased.It was also showed by determining the Zp of the stock that 'isoelectric' was reached if ahout 0. 05% chitosan was added to the stock, and it needed more chitosan to make it reach 'isoelectric' if the -coogroups of the stock increased.The mechanism study at the fiber level also showed that by increasing the fiber-to-fiber bonding and bonded area the dual additive, improved the paper strength, while the fiber strength was little affected.IR revealed that the dual additive did not change the chemical structure of the paper (i. e. did not form covalent bond with fibers), but it formed hydrogen bonds with the -OH groups at the fiber surfaces. Chitosan was inferred to form ionic bonds with the -coo groups at the fiber surfaces from the fact that chitosan improved the wet tensile strength of the paper more significantly if the -coo groups of the stock increased.The efficient filler retention of the dual additive was due to the co-flocculation caused by charge neutralization and polymer bridging.
出处
《中国造纸》
CAS
北大核心
1992年第6期27-32,共6页
China Pulp & Paper
